TY - JOUR AU - Goetzmann,William N. AU - Zhu,Ning TI - Rain or Shine: Where is the Weather Effect? JF - National Bureau of Economic Research Working Paper Series VL - No. 9465 PY - 2003 Y2 - February 2003 UR - http://www.nber.org/papers/w9465 L1 - http://www.nber.org/papers/w9465.pdf N1 - Author contact info: William N. Goetzmann School of Management Yale University Box 208200 New Haven, CT 06520-8200 Tel: 203/432-5950 Fax: 203/432-3003 E-Mail: william.goetzmann@yale.edu Ning Zhu Graduate School of Management UC, Davis One Shields Avenue Davis, CA 95616-8609 Tel: 530/752-3871 Fax: 530/752-2924 E-Mail: nzhu@saif.sjtu.edu.cn AB - Saunders (1993) and Hirshleifer and Shumway (2001) document the effect of weather on stock returns. The proposed explanation in both papers is that investor mood affects cognitive processes and trading decisions. In this paper, we use a database of individual investor accounts to examine the weather effects on traders. Our analysis of the trading activity in five major U.S. cities over a six-year period finds vistually no difference in individuals propensity to buy or sell equities on cloudy days as opposed to sunny days. If the association between cloud cover and stock returns documented for New York and other world cities is indeed caused by investor mood swings, our findings suggest that researchers should focus on the attitudes of market-makers, news providers or other agents physically located in the city hosting the exchange. NYSE spreads widen on cloudy days. When we control for this, the significance of the weather effect is dramatically reduced. We interpret this as evidence that the behavior of market-makers, rather than individual investors, may be responsible for the relation between returns and weather. ER -